Bates Numbering: Prefixes, Sequences and Stamping PDFs

What a Bates number is

A Bates number is a label printed on every page of a document set, made of a fixed prefix and a running number, such as SMITH-000412. It identifies one page and only one page across the whole set. Ordinary page numbers start again at 1 in every document; a Bates number keeps counting from the first page of the first file to the last page of the last file, so no two pages ever share a label.

The name comes from the Bates automatic numbering machine, a hand stamp that advanced by one each time it was pressed. Today the stamp is almost always added digitally to PDFs, but the idea is unchanged: once a page has its number, everyone who handles the set can point to it without describing it.

This guide explains the practice in general terms. It is not legal advice. Courts, tribunals, regulators and the parties themselves often set specific requirements, and those always come first.

Why disputes, audits and productions use them

When two sides exchange thousands of pages, vague references cause real trouble. "The email from March about the delivery" might match six emails. "DEF-002318" matches exactly one page. That precision is the whole point, and it pays off in several situations:

• Document productions and disclosure. Each side can prove what it handed over and when, because the range of numbers produced is a matter of record.
• Briefs, witness statements and hearings. A lawyer, a witness and a judge can all turn to the same page in seconds.
• Audits and regulatory responses. An auditor can cite a specific receipt or statement page in a finding, and the organisation can find it again years later.
• Spotting gaps. Because numbers run without breaks, a missing page shows up as a missing number.

Some bodies ask for it directly. The Minnesota Office of Administrative Hearings' exhibit guidance, for example, tells parties to combine the exhibit list and exhibits into one PDF and Bates-number it for easy reference. Other courts go further and prescribe the exact format, as the next section shows.

Choosing a prefix and digit count

The prefix says who produced the page or which matter it belongs to. The digits carry the sequence. Decide both before you stamp the first page, because changing either halfway through leaves you with two numbering schemes in one set.

The prefix

• Keep it short and unambiguous. Two to six capital letters is typical: a party's initials, a client code or a matter abbreviation.
• Use a different prefix for each producing party. If both sides start at 000001, a reference to "page 000001" is ambiguous again; PLT- and DEF- fixes that.
• Decide the separator once. A hyphen, an underscore or nothing at all are all common. Whatever you choose, type it exactly the same way every time.
• Follow any rule you are given. In one set of procedures from the US Court of International Trade, appendix pages must use the prefix "Appx" followed directly by the number, with no spaces or other characters in between; leading zeros are optional there, and public record pages start at Appx1000 while confidential pages start at Appx80000 (Judge Vaden's joint appendix procedures). That is one judge's rule for one kind of filing, which is exactly why you should check your own forum's rules rather than copy a format from elsewhere.
• Stick to plain Latin characters. PDFora stamps with a standard font that only covers Western European characters, so a prefix in Cyrillic, Greek, Devanagari or Chinese cannot be drawn. Letters A to Z, digits, hyphens and underscores are safe everywhere.

The digit count

Zero-padding keeps every label the same length, which makes them sort correctly in spreadsheets and file lists (000099 sorts before 000100, while unpadded 99 sorts after 100 as text). Pick a width comfortably larger than the biggest set you can imagine:

Digits	Highest number	Example label	Suits
4	9,999	ABC-0042	Small tribunal bundles, a single audit file
5	99,999	ABC-00042	Medium disputes and regulatory responses
6	999,999	ABC-000042	Most commercial productions; PDFora's default
7	9,999,999	ABC-0000042	Very large, multi-custodian productions

Six digits is a sensible default. If a set ever outgrows its width, the numbers do not wrap round; they simply get one digit longer, which breaks the neat sorting but not the uniqueness.

Numbering several files in sequence

Real productions are rarely a single PDF. You might have a folder of contracts, a batch of email exports and a few scanned letters. The rule is simple: the start number of each file is the last number of the previous file plus one, and the last number of any file is its start number plus its page count minus one.

1. Put the files in the order you want them produced and write that order down.
2. Note each file's page count before stamping anything.
3. Stamp the first file starting at 1 (or whatever start you have been told to use).
4. Work out the next start: previous start + previous page count.
5. Stamp the next file, check its last page, and repeat.

A worked example with the prefix ABC- and six digits:

File	Pages	Start	First label	Last label
supply-agreement.pdf	37	1	ABC-000001	ABC-000037
emails-march.pdf	112	38	ABC-000038	ABC-000149
delivery-notes-scan.pdf	9	150	ABC-000150	ABC-000158

Check the arithmetic on the middle row: 38 + 112 − 1 = 149, so the next file starts at 150. An off-by-one slip here creates either a duplicate label or a gap, and both look careless to whoever receives the set.

The alternative is to join everything first with Merge PDF and stamp the combined file in one pass. That removes the arithmetic entirely and matches guidance that asks for a single combined, numbered PDF. The trade-off is that you lose the separate files, so keep the unmerged originals and record in your index where each document begins and ends.

Where to place the stamp

Bottom right is the most widely used position, because it sits where a reader's thumb and eye land when flipping pages, and it rarely collides with letterheads. Bottom left and bottom centre are the usual alternatives when the right corner is busy.

Before committing, look at the pages most likely to cause trouble:

• Pages with existing footers. Invoices, bank statements and slide exports often have small print right at the bottom edge. If the label lands on top of it, choose another corner.
• Pages that already carry page numbers. Avoid putting the Bates label in the same corner as an existing "Page 3 of 10", or readers will confuse the two.
• Landscape and rotated pages. A spreadsheet printout scanned sideways may show the label along a side edge rather than the bottom. Fix the orientation with Rotate PDF before stamping if that matters to you.
• Other legends. A confidentiality marking such as "CONFIDENTIAL – SUBJECT TO PROTECTIVE ORDER" usually goes in a different place from the number. Header & Footer centres its text at the top or bottom, so a header line leaves a bottom-corner Bates label clear.

One more ordering rule: do any redaction and page removal before numbering. If you stamp first and then delete a page, you have created a gap you will have to explain.

Keeping an index spreadsheet

The labels on the pages are only half of the system. The other half is a log that says which range is which document. Start it with the first file and add a row every time you stamp. A minimal version has these columns:

Bates start	Bates end	Pages	File name	Description	Source	Status
ABC-000001	ABC-000037	37	supply-agreement-bates.pdf	Signed supply agreement, 2024	Sales director	Produced 12 Nov
ABC-000038	ABC-000149	112	emails-march-bates.pdf	Delivery emails, March	Shared mailbox	Produced 12 Nov

Add a formula column that checks end − start + 1 = pages for every row, and a second that checks each start equals the previous end plus one. Two quick formulas catch most numbering mistakes before the other side does. Depending on the matter, you may also want columns for confidentiality level, privilege review outcome, date produced and recipient.

If a page has to be withheld after numbering, a common approach is to replace it with a placeholder page that carries the same number and says why it was withheld, rather than renumbering everything that follows. Agree how to handle this with the other side or follow the rules you are under, and note it in the index.

Using PDFora's Bates Numbering

Bates Numbering stamps one PDF per run, entirely in your browser, so files containing personal or privileged material are not uploaded anywhere. For a multi-file set, run it once per file using the arithmetic above.

1. Open the tool and load the file that comes next in your production order.
2. Enter the prefix character for character as it appears in your index, separator included. An empty prefix gives bare numbers.
3. Enter the start number. Zero is accepted if your scheme starts there.
4. Set the digit count (6 unless you have a reason to change it) and the position: bottom right, bottom left or bottom centre.
5. Add the numbers and download the file, which is saved with -bates added to its name.
6. Open the result, check the first and last label against your plan, and fill in the index row before moving on.

PDFora sets the stamp in near-black 10-point Helvetica, about 6 mm above the bottom edge and about 8.5 mm in from the side edge for the corner positions (24 points; one point is 1/72 inch, so 24 points is one third of an inch). It sits on top of the existing page content and becomes part of the page, so keep an unstamped copy of every original. Because the font covers Western European characters only, keep the prefix to plain letters, digits and simple punctuation.

The tool applies the stamp; it does not know your court's or regulator's rules. Whether a given prefix, position or numbering scheme is acceptable in your matter is for you or your adviser to confirm.